Initial commit

include/screen.h

@@ -0,0 +1,42 @@
+// screen.h
+#ifndef SCREEN_H
+#define SCREEN_H
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+/* Hardware text mode color constants. */
+enum vga_color {
+        VGA_COLOR_BLACK = 0,
+        VGA_COLOR_BLUE = 1,
+        VGA_COLOR_GREEN = 2,
+        VGA_COLOR_CYAN = 3,
+        VGA_COLOR_RED = 4,
+        VGA_COLOR_MAGENTA = 5,
+        VGA_COLOR_BROWN = 6,
+        VGA_COLOR_LIGHT_GREY = 7,
+        VGA_COLOR_DARK_GREY = 8,
+        VGA_COLOR_LIGHT_BLUE = 9,
+        VGA_COLOR_LIGHT_GREEN = 10,
+        VGA_COLOR_LIGHT_CYAN = 11,
+        VGA_COLOR_LIGHT_RED = 12,
+        VGA_COLOR_LIGHT_MAGENTA = 13,
+        VGA_COLOR_LIGHT_BROWN = 14,
+        VGA_COLOR_WHITE = 15,
+};
+
+static const size_t VGA_WIDTH = 80;
+static const size_t VGA_HEIGHT = 25;
+
+uint8_t vga_entry_color(enum vga_color fg, enum vga_color bg);
+uint16_t vga_entry(unsigned char uc, uint8_t color);
+size_t strlen(const char* str);
+void terminal_initialize(void);
+void terminal_setcolor(uint8_t color);
+void terminal_putentryat(char c, uint8_t color, size_t x, size_t y);
+void terminal_putchar(char c);
+void terminal_write(const char* data, size_t size);
+void terminal_writestring(const char* data);
+
+#endif